1. Field of the Invention
The present invention relates generally to MIDI devices, and more particularly to MIDI controllers.
2. Description of Related Art
Electronic musical instruments have become common in which sounds are produced by the playing of keys by a musician and stored as digital data on a recording medium. Such electrical instruments may be interfaced with other electrical devices such as synthesizers, controllers, and other instruments. A standard interface protocol used in the operation of electronic instruments and musical apparatuses, including synthesizers, keyboards, and controllers, is Musical Instrument Digital Interface (MIDI). Before discussing the aspects of MIDI, it is important to understand a few basic principles surrounding musical instruments. All musical instruments have the capability of making a variety of sounds by some means. Herein the action of starting a sound will be referred to as a “Note-On.” Instruments generally also have some means of stopping the sound at a given time. This action will be referred to as “Note-Off.” Most instruments also possess the ability to vary such sound components as volume and pitch. For example, the harder a pianist hits a particular key on the keyboard, the louder a given note sounds.
A MIDI device may contain three jacks for connection to other media including, a MIDI In, a MIDI Out, and a MIDI Thru. Each jack is a female 5-pin Deutsche Industrinorm (DIN) jack as standard on personal computers. When connecting two MIDI devices, the MIDI Out of one device connects to the MIDI In of the other device. To connect multiple devices together, each successive device has its MIDI In connected to the MIDI Thru of the previous device, this is referred to as daisy chaining. MIDI supports 16 channels through which information can be transmitted. Each individual device may be programmed to respond only when signals from a particular channel arrive. Should signals from other channels reach an attached device, it merely passes the signals on to the next device in the daisy chain. In this manner, a single controller can be used to operate a plurality of musical devices, and have separate control over each device.
In essence MIDI is a set of musical commands which are achieved through mulit-byte messages, each consisting of usually one status byte followed by one or two data bytes. These commands contain all of the information necessary to play a musical instrument such as “Note-On”, “Note-Off”, velocity, pitch, and aftertouch. The main advantages of MIDI are that it is easily edited, and is a compact form of data. MIDI “notes” and other musical actions, such as moving the pitch wheel or pressing the sustain pedal are separated by messages on different channels. This allows the musician to store the messages generated by many instruments in a single compact file, while retaining the ability for messages to be easily separated by instrument because the MIDI messages for each instrument are on a different MIDI channel.
Most MIDI controllers permit a high degree of control over the characteristics of the sound being produced. Such characteristics may include the MIDI channel number, the audio pan, the volume, the modulation, the aftertouch, etc. The term for this collection of settings is “patch.” It is desirable for the controller or controllers used to have the ability to easily and readily change each patch setting, without inhibiting the playing of the instruments and/or synthesizers being controlled.